Eduardo A. Salgado wrote:

>OK, I'll look into it.
>
>Now, implementing your other suggestions ... worked!
>
>I identified some 6 really bad indexes and deleted them.
>
>Sweep was then instantaneous!
>
>Back up took just 7:01 minutes and Restore about 20 minutes. Success!
>
>

Good to hear it ! :-)

>Now, since I have you on the line, refresh me again on how to turn
>indexes with low selectivity into better indexes. I am about to test
>some queries for timing with and without the indexes. So, building
>better selective indexes will help a lot.
>
>

To minimize the impact of low selectivity indices on sweep you could
make it a compound index adding the PK as the second column.

But I don't think it will help on filter conditions, I think a Natural
scan should perform better than a navigational indexed scan using an
index wich has few distinct values. Try it with and without the indices
and lets see what the results will be.

>Thanks!
>
>-Eduardo
>
>

see you !

--

Alexandre Benson Smith
Development
THOR Software e Comercial Ltda.
Santo Andre - Sao Paulo - Brazil
www.thorsoftware.com.br



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